HIV & OPPORTUNISTIC INFECTIONS

Opportunistic infections are infections caused by organisms that usually do not cause disease in a person with a healthy immune system, but can affect people with a poorly functioning or suppressed immune system. They need an "opportunity" to infect a person

In our bodies, we carry many germs - bacteria, protozoa, fungi, and viruses. When our immune system is working, it controls these germs. But when the immune system is weakened by HIV disease or by some medications, these germs can get out of control and cause health problems.

Infections that take advantage of weakness in the immune defenses are called "opportunistic". The phrase "opportunistic infection" is often shortened to "OI".

You can be infected with an OI, and "test positive" for it, even though you don't have the disease. For example, almost everyone with HIV tests positive for Cytomegalovirus (CMV). But it is very rare for CMV disease to develop unless the CD4 cell count drops below 50, a sign of serious damage to the

immune system.
To see if you're infected with an OI, your blood might be tested for antigens (pieces of the germ that causes the OI) or for antibodies (proteins made by the immune system to fight the germs). If the antigens are found, it means you’re infected. If the antibodies are found, you’ve been exposed to the infection. You may have been immunized against the infection, or your immune system may have cleared? The infection or you may be infected. If you are infected with a germ that causes an OI, and if your CD4 cells are low enough to allow that OI to develop, your health care provider will look for signs of active disease. These are different for the different OIs.

People who aren't HIV-infected can develop OIs if their immune systems are damaged. For example, many drugs used to treat cancer suppress the immune system. Some people who get cancer treatments can develop OIs.

The following are just a few of the OPPORTUNISTIC INFECTIONS that particularly affect people living with HIV.

Bacterial pneumonia
Pneumonia can be caused by various bacteria. Symptoms among HIV-positive people are much the same as in those without HIV infection, and include chills, rigors, chest pain and pus in the sputum. Because other forms of respiratory infection including PCP are common among HIV-infected people, doctors must be certain of diagnosis before administering antibiotics. This may require a chest radiograph, blood cultures, a white blood cell count and tests to eliminate other infections. Treatment is usually aimed at the most commonly identified disease-causing bacteria.

Candidacies
There are two main types of candidacies: localized disease (of the mouth and throat or of the vagina) and systemic disease (of the esophagus, and disseminated disease). The mouth and throat variant (commonly known as thrush or OPC) is believed to occur at least once in the lifetime of all HIV-infected patients. Occurrence of the vaginal variant is common among healthy women and is unrelated to HIV status.

Cryptococcus
Cryptococcus is caused by a fungus that primarily infects the brain. It most often appears as meningitis and occasionally as pulmonary or disseminated disease. Untreated Cryptococcus meningitis is fatal.

Cryptococcus is relatively easy to diagnose. However, its treatment and secondary chemoprophylaxis are often impossible in developing countries because of high cost and limited availability of the drugs required.

Cryptosporidiosis and isosporiasis
Cryptosporidiosis (crypto) and isosporiasis are both caused by protozoan parasites. These diseases are easily spread by contaminated food or water, or by direct contact with an infected person or animal. Both crypto and isosporiasis cause diarrhea, nausea, vomiting and stomach cramps. In people with healthy immune systems, these symptoms do not last more than about a week. However, if the immune system is damaged then they can continue for a long time. Diarrhea can interfere with the absorption of nutrients and this can lead to serious weight loss.

To confirm diagnosis of either disease, the stool is normally checked for parasites and their eggs. There is no cure for crypto, but antiretroviral therapy to restore immunity can effectively clear up the infection.

Cytomegalovirus
Cytomegalovirus (CMV) is a virus that infects the whole body. It most commonly appears as retinitis, which causes blurred vision and can lead to blindness. CMV can also affect other organs, and is capable of causing fever, diarrhea, nausea, pneumonia-like symptoms and dementia.

Herpes simplex and Herpes zoster
The usual symptoms of herpes simplex virus infection (HSV, which causes sores around the mouth and genitals) and herpes zoster virus infection ('zonal' herpes or shingles) are not life-threatening but can be extremely painful. Both viruses are also capable of causing retinitis and encephalitis (which can be life-threatening).

Histoplasmosis
Histoplasmosis is a fungal infection that primarily affects the lungs but may also affect other organs. Symptoms can include fever, fatigue, weight loss and difficulty in breathing.

Disseminated histoplasmosis infection may be diagnosed using an antigen test, and can be fatal if left untreated.

Kaposi's sarcoma
HIV-associated Kaposi's sarcoma causes dark blue lesions, which can occur in a variety of locations including the skin, mucous membranes, gastrointestinal tract, lungs or lymph nodes. The lesions usually appear early in the course of HIV infection.

Leishmaniasis
Leishmaniasis is transmitted by sand flies and possibly through sharing needles. The most serious of its four forms is visceral leishmaniasis (also know as kala azar) which is characterized by irregular bouts of fever, substantial weight loss, swelling of the spleen and liver and anemia (occasionally serious). In its more common forms, leishmaniasis can produce disfiguring lesions around the nose, mouth and throat, or skin ulcers leading to permanent scarring.

Treatment of leishmaniasis with pentavalent antimony is relatively expensive, partly because of the cost of drugs but also because hospital admission is recommended (in milder cases, trained health workers may administer the injections or infusions at a patient's home). If left untreated, visceral leishmaniasis is usually fatal.

MAC
The germs of the mycobacterium avium complex (MAC) are related to the germ that causes tuberculosis. MAC disease generally affects multiple organs, and symptoms include fever, night sweats, weight loss, fatigue, diarrhea and abdominal pain.

MAC should be treated using at least two antimycobacterial drugs to prevent or delay the emergence of resistance.

PCP
PCP is caused by a parasite that infects the lungs, which was formerly called pneumocystis carinii but has now been renamed pneumocystis jiroveci. PCP is a frequent HIV associated opportunistic infection in industrialized countries but appears to be less common in Africa . The symptoms are mainly pneumonia along with fever and respiratory symptoms such as dry cough, chest pain and dyspnoea. Definitive diagnosis requires microscopy of bodily tissues or fluids.

Prevention of PCP is strongly recommended for HIV-infected persons with very weak immune systems wherever PCP is a significant health problem for HIV-infected persons, and also after their first episode of PCP.

Toxoplasmosis
Toxoplasmosis (toxo) is caused by a protozoan found in uncooked meat and cat faeces. This microbe infects the brain and can cause headache, confusion, motor weakness and fever. In the absence of treatment, disease progression results in seizures, stupour and coma. Disseminated toxo is less common, but can affect the eyes and cause pneumonia.

Tuberculosis
Tuberculosis (TB) is a bacterial infection that primarily infects the lungs. Tuberculosis is the leading HIV-associated opportunistic disease in developing countries. For people who are dually infected with HIV and TB, the risk of developing active tuberculosis is 30-50 folds higher than for people infected with TB alone. And because mycobacterium can spread through the air, the increase in active TB cases among dually infected people means:

More transmission of the TB germ
More TB carriers
More TB in the whole population.
Tuberculosis is harder to diagnose in HIV-positive people than in those who are uninfected. The diagnosis of TB is important because TB progresses faster in HIV-infected people. Also, TB in HIV-positive people is more likely to be fatal if undiagnosed or left untreated. TB occurs earlier in the course of HIV infection than many other opportunistic infections.

A proper combination of anti-TB drugs achieves both prevention and cure. Effective treatment quickly makes the individual non-contagious, which prevents further spread of the TB germ. The DOTS (directly observed short course) treatment strategy recommended by WHO treats TB in HIV-infected persons as effectively as it treats those without the virus. A complete cure takes 6 to 8 months and uses a combination of antibiotics. In addition to curing the individual, it also prevents further spread of the disease to others. This is why treating infectious cases of TB has important benefits for society as a whole.

The Human Immunodeficiency Virus (HIV), which causes AIDS, is easily transmitted through blood transfusions. In fact, the chances that someone who has received a transfusion with HIV blood will himself or herself become infected are estimated to be over
Blood transfusions will always carry certain risks, but HIV transmission through blood transfusion can virtually be prevented. One can do this by setting up and maintaining a safe blood supply and by using the blood appropriately. One should always ensure that the blood is screened for the presence of diseases causing viruses, bacteria, or other microorganisms, or for the presence of anti bodies produced against these agents.

All donated blood must be screened for HIV, as well as for hepatitis B and syphilis (and hepatitis C where ever possible). In addition, both doctors and patients must be aware that blood should be used only for necessary transfusion. While it is important to take necessary precautions, we also must keep in mind that if each individual is to donate blood once a year voluntarily, the total requirement of blood worldwide would be met.

Transfusion
Is it safe to have blood transfusion?

Blood transfusion saves millions of lives each year, but only if safe blood supply is guaranteed. Receiving transfused blood has increased the risk to being affected by HIV and a number of other infections. Diseases such as hepatitis B, hepatitis C and several Sexually Transmitted Diseases (STDs) can also be transmitted through transfusion.

Can I receive my own blood?
Your own blood is the safest blood for your transfusion needs. A transfusion, after all, is a transplant of sorts, but instead of a kidney or liver, blood is the tissue a patient receives. When transfused with your own blood, you are not exposed to infectious disease and you are the perfect match. Your doctor will also carefully consider the benefits and affects your blood donations may have on you.

How do I ensure that the blood is actually HIV free?
The process of testing blood to see if it contains infectious agents capable of being transmitted to those who received the blood is known as screening. Majority of tests detect the presence of anti bodies to HIV and not the virus itself. Although HIV tests are very sensitive, there is a window period. This is the period between the onset of infection with HIV and the appearance of detectable anti bodies to the virus. In the case of most sensitive HIV tests the window period is about three weeks.

Voluntary Donation of Blood

Who can donate blood?
Every healthy individual with no known infection /disease can donate blood. It should still be done after having screened yourself. The donor should be in good health and should be feeling well on the day they donate. He/she should weigh at least 110 lbs. (50 kg) or more, not on any prescribed medication that may affect the donor or recipient. There should be a gap of at least 56 days between donations.

How often can I donate blood?
Donating blood over thrice a year is not recommended. Excessive donation results in blood becoming substandard, for instance lacking in iron. It can also affect the donor's health.

Where can I donate blood?
One can donate blood at any licensed blood bank and blood donation camp.

Why should I donate blood?
The safest type of blood donor is the voluntary, unpaid donor. Such donor gives out of altruism, and is not under pressure to donate blood. On the whole, such donors are more likely to meet the criteria for low risk donors. And they are also more likely to be willing to donate on a regular basis and at properly spaced intervals. This is important in maintaining a sufficient stock of blood.

How will it be used?
Blood is often used as a replacement of the quantity given to an individual by a medical practitioner. In this system, families of people needing a transfusion are asked to donate the same quantity as that given to their relative and this blood may be used directly, where compatible, or else put into the general pool.

Is blood donation harmful?
No, if it is at properly spaced intervals and is donated at licensed blood banks/camps it is not harmful. Many donors have given blood over 50 times, up to four times a year, without any harm to their health. If you are healthy, you can give blood every 56 days.

Can you get HIV by donating blood?
It is safe to give blood. You cannot contract any diseases through blood donation if the needle and other clinic materials used to take blood are new, sterile and used only once. If you are donating at licensed banks, these safety conditions will be definitely adhered to. The materials used are disposed after one use.

Rational Use

When?
Doctors and other medical staff should be educated to avoid prescribing inappropriate transfusion. Blood substitutes should be used only when it is appropriate. Simple alternatives to blood, such as crystalloids or colloids, will not transmit infection and can be obtained at a fraction of the cost of whole blood.
One of the reasons, which make blood supply unsafe is shortage. This shortage can be addressed to a great extent by transfusing blood components instead of whole blood. Wherever whole blood is not needed, the appropriate component should be used.

The underlying reasons for blood transfusion should be addressed. A condition for which blood transfusions are often given is chronic anemia, which results from the lack of red blood cells that carry oxygen to the tissues. Chronic anemia can be caused by malnutrition, slow loss of blood and infection such as malaria. If the root cause of chronic anemia is attacked, we can manage the condition. Another condition where blood is often needed is childbirth-related emergencies. By taking proper care of women before and during delivery, we can decrease the need for transfusion.

Avoid unnecessary transfusion
Transfusion is not always necessary or appropriate. Avoid using single-unit transfusions.

Transfusion increases the risk of transmitting HIV, especially in places where there is no adequate screening of blood. Apart from that, it creates an unavoidable shortage in blood supply. This encourages professional donors to become more active, reducing the safety of the supply.

What is it used for?
Blood donations are used for a number of purposes:

Red blood cells are transfused when an illness leads to anemia.
Platelets are needed where bone marrow cannot work properly for example, anti-cancer treatment, or in patients who cannot produce normal platelets to clot the blood.
White blood cells are important to help patients whose resistance to serious infection is low, such as during cancer treatment.
Plasma is used for critically ill patients who have lost a large volume of blood and need a replacement of the full range of proteins contained in plasma.
Blood is used in cases of acute blood loss, such as after accidents or during an operation.
Risks

All blood donations are tested thoroughly for certain viruses, but it is not always possible to detect them at the earliest stage of the infection. Very occasionally, viruses such as HIV, hepatitis B and C can take several weeks after someone is infected to show up in tests. This means that blood that does not show any signs of infection could still pass on a disease.